nativepower: Rename "chromeos" -> "brillo" in include paths and namespaces

libchromeos is transitioning to libbrillo and chromeos namespaces
and include directory is changing to brillo.

Bug: 24872993
TEST=dragonboard builds & launches
     unit tests for nativepowerman_tests and libnativepower_tests pass

Change-Id: If77ddddd4740cea828fb343a1dbdc007c61b6b52
2 files changed